/*
* u_ether.c -- Ethernet-over-USB link layer utilities for Gadget stack
*
* Copyright (C) 2003-2005,2008 David Brownell
* Copyright (C) 2003-2004 Robert Schwebel, Benedikt Spranger
* Copyright (C) 2008 Nokia Corporation
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*/
/* #define VERBOSE_DEBUG */
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/gfp.h>
#include <linux/device.h>
#include <linux/ctype.h>
#include <linux/etherdevice.h>
#include <linux/ethtool.h>
#include <linux/if_vlan.h>
#include "u_ether.h"
/*
* This component encapsulates the Ethernet link glue needed to provide
* one (!) network link through the USB gadget stack, normally "usb0".
*
* The control and data models are handled by the function driver which
* connects to this code; such as CDC Ethernet (ECM or EEM),
* "CDC Subset", or RNDIS. That includes all descriptor and endpoint
* management.
*
* Link level addressing is handled by this component using module
* parameters; if no such parameters are provided, random link level
* addresses are used. Each end of the link uses one address. The
* host end address is exported in various ways, and is often recorded
* in configuration databases.
*
* The driver which assembles each configuration using such a link is
* responsible for ensuring that each configuration includes at most one
* instance of is network link. (The network layer provides ways for
* this single "physical" link to be used by multiple virtual links.)
*/
#define UETH__VERSION "29-May-2008"
static struct workqueue_struct *uether_wq;
struct eth_dev {
/* lock is held while accessing port_usb
*/
spinlock_t lock;
struct gether *port_usb;
struct net_device *net;
struct usb_gadget *gadget;
spinlock_t req_lock; /* guard {rx,tx}_reqs */
struct list_head tx_reqs, rx_reqs;
unsigned tx_qlen;
/* Minimum number of TX USB request queued to UDC */
#define TX_REQ_THRESHOLD 5
int no_tx_req_used;
int tx_skb_hold_count;
u32 tx_req_bufsize;
struct sk_buff_head rx_frames;
unsigned header_len;
unsigned ul_max_pkts_per_xfer;
unsigned dl_max_pkts_per_xfer;
struct sk_buff *(*wrap)(struct gether *, struct sk_buff *skb);
int (*unwrap)(struct gether *,
struct sk_buff *skb,
struct sk_buff_head *list);
struct work_struct work;
struct work_struct rx_work;
unsigned long todo;
#define WORK_RX_MEMORY 0
bool zlp;
u8 host_mac[ETH_ALEN];
};
/*-------------------------------------------------------------------------*/
#define RX_EXTRA 20 /* bytes guarding against rx overflows */
#define DEFAULT_QLEN 2 /* double buffering by default */
static unsigned qmult = 10;
module_param(qmult, uint, S_IRUGO|S_IWUSR);
MODULE_PARM_DESC(qmult, "queue length multiplier at high/super speed");
/* for dual-speed hardware, use deeper queues at high/super speed */
static inline int qlen(struct usb_gadget *gadget)
{
if (gadget_is_dualspeed(gadget) && (gadget->speed == USB_SPEED_HIGH ||
gadget->speed == USB_SPEED_SUPER))
return qmult * DEFAULT_QLEN;
else
return DEFAULT_QLEN;
}
/*-------------------------------------------------------------------------*/
/* REVISIT there must be a better way than having two sets
* of debug calls ...
*/
#undef DBG
#undef VDBG
#undef ERROR
#undef INFO
#define xprintk(d, level, fmt, args...) \
printk(level "%s: " fmt , (d)->net->name , ## args)
#ifdef DEBUG
#undef DEBUG
#define DBG(dev, fmt, args...) \
xprintk(dev , KERN_DEBUG , fmt , ## args)
#else
#define DBG(dev, fmt, args...) \
do { } while (0)
#endif /* DEBUG */
#ifdef VERBOSE_DEBUG
#define VDBG DBG
#else
#define VDBG(dev, fmt, args...) \
do { } while (0)
#endif /* DEBUG */
#define ERROR(dev, fmt, args...) \
xprintk(dev , KERN_ERR , fmt , ## args)
#define INFO(dev, fmt, args...) \
xprintk(dev , KERN_INFO , fmt , ## args)
/*-------------------------------------------------------------------------*/
/* NETWORK DRIVER HOOKUP (to the layer above this driver) */
static int ueth_change_mtu(struct net_device *net, int new_mtu)
{
struct eth_dev *dev = netdev_priv(net);
unsigned long flags;
int status = 0;
/* don't change MTU on "live" link (peer won't know) */
spin_lock_irqsave(&dev->lock, flags);
if (dev->port_usb)
status = -EBUSY;
else if (new_mtu <= ETH_HLEN || new_mtu > ETH_FRAME_LEN)
status = -ERANGE;
else
net->mtu = new_mtu;
spin_unlock_irqrestore(&dev->lock, flags);
return status;
}
static void eth_get_drvinfo(struct net_device *net, struct ethtool_drvinfo *p)
{
struct eth_dev *dev = netdev_priv(net);
strlcpy(p->driver, "g_ether", sizeof(p->driver));
strlcpy(p->version, UETH__VERSION, sizeof(p->version));
strlcpy(p->fw_version, dev->gadget->name, sizeof(p->fw_version));
strlcpy(p->bus_info, dev_name(&dev->gadget->dev), sizeof(p->bus_info));
}
/* REVISIT can also support:
* - WOL (by tracking suspends and issuing remote wakeup)
* - msglevel (implies updated messaging)
* - ... probably more ethtool ops
*/
static const struct ethtool_ops ops = {
.get_drvinfo = eth_get_drvinfo,
.get_link = ethtool_op_get_link,
};
static void defer_kevent(struct eth_dev *dev, int flag)
{
if (test_and_set_bit(flag, &dev->todo))
return;
if (!schedule_work(&dev->work))
ERROR(dev, "kevent %d may have been dropped\n", flag);
else
DBG(dev, "kevent %d scheduled\n", flag);
}
static void rx_complete(struct usb_ep *ep, struct usb_request *req);
static int
rx_submit(struct eth_dev *dev, struct usb_request *req, gfp_t gfp_flags)
{
struct sk_buff *skb;
int retval = -ENOMEM;
size_t size = 0;
struct usb_ep *out;
unsigned long flags;
spin_lock_irqsave(&dev->lock, flags);
if (dev->port_usb)
out = dev->port_usb->out_ep;
else
out = NULL;
spin_unlock_irqrestore(&dev->lock, flags);
if (!out)
return -ENOTCONN;
/* Padding up to RX_EXTRA handles minor disagreements with host.
* Normally we use the USB "terminate on short read" convention;
* so allow up to (N*maxpacket), since that memory is normally
* already allocated. Some hardware doesn't deal well with short
* reads (e.g. DMA must be N*maxpacket), so for now don't trim a
* byte off the end (to force hardware errors on overflow).
*
* RNDIS uses internal framing, and explicitly allows senders to
* pad to end-of-packet. That's potentially nice for speed, but
* means receivers can't recover lost synch on their own (because
* new packets don't only start after a short RX).
*/
size += sizeof(struct ethhdr) + dev->net->mtu + RX_EXTRA;
size += dev->port_usb->header_len;
size += out->maxpacket - 1;
size -= size % out->maxpacket;
if (dev->ul_max_pkts_per_xfer)
size *= dev->ul_max_pkts_per_xfer;
if (dev->port_usb->is_fixed)
size = max_t(size_t, size, dev->port_usb->fixed_out_len);
DBG(dev, "%s: size: %d\n", __func__, size);
skb = alloc_skb(size + NET_IP_ALIGN, gfp_flags);
if (skb == NULL) {
DBG(dev, "no rx skb\n");
goto enomem;
}
/* Some platforms perform better when IP packets are aligned,
* but on at least one, checksumming fails otherwise. Note:
* RNDIS headers involve variable numbers of LE32 values.
*/
skb_reserve(skb, NET_IP_ALIGN);
req->buf = skb->data;
req->length = size;
req->complete = rx_complete;
req->context = skb;
retval = usb_ep_queue(out, req, gfp_flags);
if (retval == -ENOMEM)
enomem:
defer_kevent(dev, WORK_RX_MEMORY);
if (retval) {
DBG(dev, "rx submit --> %d\n", retval);
if (skb)
dev_kfree_skb_any(skb);
}
return retval;
}
static void rx_complete(struct usb_ep *ep, struct usb_request *req)
{
struct sk_buff *skb = req->context;
struct eth_dev *dev = ep->driver_data;
int status = req->status;
bool queue = 0;
switch (status) {
/* normal completion */
case 0:
skb_put(skb, req->actual);
if (dev->unwrap) {
unsigned long flags;
spin_lock_irqsave(&dev->lock, flags);
if (dev->port_usb) {
status = dev->unwrap(dev->port_usb,
skb,
&dev->rx_frames);
if (status == -EINVAL)
dev->net->stats.rx_errors++;
else if (status == -EOVERFLOW)
dev->net->stats.rx_over_errors++;
} else {
dev_kfree_skb_any(skb);
status = -ENOTCONN;
}
spin_unlock_irqrestore(&dev->lock, flags);
} else {
skb_queue_tail(&dev->rx_frames, skb);
}
if (!status)
queue = 1;
break;
/* software-driven interface shutdown */
case -ECONNRESET: /* unlink */
case -ESHUTDOWN: /* disconnect etc */
VDBG(dev, "rx shutdown, code %d\n", status);
goto quiesce;
/* for hardware automagic (such as pxa) */
case -ECONNABORTED: /* endpoint reset */
DBG(dev, "rx %s reset\n", ep->name);
defer_kevent(dev, WORK_RX_MEMORY);
quiesce:
dev_kfree_skb_any(skb);
goto clean;
/* data overrun */
case -EOVERFLOW:
dev->net->stats.rx_over_errors++;
/* FALLTHROUGH */
default:
queue = 1;
dev_kfree_skb_any(skb);
dev->net->stats.rx_errors++;
DBG(dev, "rx status %d\n", status);
break;
}
clean:
spin_lock(&dev->req_lock);
list_add(&req->list, &dev->rx_reqs);
spin_unlock(&dev->req_lock);
if (queue)
queue_work(uether_wq, &dev->rx_work);
}
static int prealloc(struct list_head *list, struct usb_ep *ep, unsigned n)
{
unsigned i;
struct usb_request *req;
if (!n)
return -ENOMEM;
/* queue/recycle up to N requests */
i = n;
list_for_each_entry(req, list, list) {
if (i-- == 0)
goto extra;
}
while (i--) {
req = usb_ep_alloc_request(ep, GFP_ATOMIC);
if (!req)
return list_empty(list) ? -ENOMEM : 0;
list_add(&req->list, list);
}
return 0;
extra:
/* free extras */
for (;;) {
struct list_head *next;
next = req->list.next;
list_del(&req->list);
usb_ep_free_request(ep, req);
if (next == list)
break;
req = container_of(next, struct usb_request, list);
}
return 0;
}
static int alloc_requests(struct eth_dev *dev, struct gether *link, unsigned n)
{
int status;
spin_lock(&dev->req_lock);
status = prealloc(&dev->tx_reqs, link->in_ep, n);
if (status < 0)
goto fail;
status = prealloc(&dev->rx_reqs, link->out_ep, n);
if (status < 0)
goto fail;
goto done;
fail:
DBG(dev, "can't alloc requests\n");
done:
spin_unlock(&dev->req_lock);
return status;
}
static void rx_fill(struct eth_dev *dev, gfp_t gfp_flags)
{
struct usb_request *req;
unsigned long flags;
int req_cnt = 0;
/* fill unused rxq slots with some skb */
spin_lock_irqsave(&dev->req_lock, flags);
while (!list_empty(&dev->rx_reqs)) {
/* break the nexus of continuous completion and re-submission*/
if (++req_cnt > qlen(dev->gadget))
break;
req = container_of(dev->rx_reqs.next,
struct usb_request, list);
list_del_init(&req->list);
spin_unlock_irqrestore(&dev->req_lock, flags);
if (rx_submit(dev, req, gfp_flags) < 0) {
spin_lock_irqsave(&dev->req_lock, flags);
list_add(&req->list, &dev->rx_reqs);
spin_unlock_irqrestore(&dev->req_lock, flags);
defer_kevent(dev, WORK_RX_MEMORY);
return;
}
spin_lock_irqsave(&dev->req_lock, flags);
}
spin_unlock_irqrestore(&dev->req_lock, flags);
}
static void process_rx_w(struct work_struct *work)
{
struct eth_dev *dev = container_of(work, struct eth_dev, rx_work);
struct sk_buff *skb;
int status = 0;
if (!dev->port_usb)
return;
while ((skb = skb_dequeue(&dev->rx_frames))) {
if (status < 0
|| ETH_HLEN > skb->len
|| skb->len > ETH_FRAME_LEN) {
dev->net->stats.rx_errors++;
dev->net->stats.rx_length_errors++;
DBG(dev, "rx length %d\n", skb->len);
dev_kfree_skb_any(skb);
continue;
}
skb->protocol = eth_type_trans(skb, dev->net);
dev->net->stats.rx_packets++;
dev->net->stats.rx_bytes += skb->len;
status = netif_rx_ni(skb);
}
if (netif_running(dev->net))
rx_fill(dev, GFP_KERNEL);
}
static void eth_work(struct work_struct *work)
{
struct eth_dev *dev = container_of(work, struct eth_dev, work);
if (test_and_clear_bit(WORK_RX_MEMORY, &dev->todo)) {
if (netif_running(dev->net))
rx_fill(dev, GFP_KERNEL);
}
if (dev->todo)
DBG(dev, "work done, flags = 0x%lx\n", dev->todo);
}
static void tx_complete(struct usb_ep *ep, struct usb_request *req)
{
struct sk_buff *skb = req->context;
struct eth_dev *dev = ep->driver_data;
struct net_device *net = dev->net;
struct usb_request *new_req;
struct usb_ep *in;
int length;
int retval;
switch (req->status) {
default:
dev->net->stats.tx_errors++;
VDBG(dev, "tx err %d\n", req->status);
/* FALLTHROUGH */
case -ECONNRESET: /* unlink */
case -ESHUTDOWN: /* disconnect etc */
break;
case 0:
if (!req->zero)
dev->net->stats.tx_bytes += req->length-1;
else
dev->net->stats.tx_bytes += req->length;
}
dev->net->stats.tx_packets++;
spin_lock(&dev->req_lock);
list_add_tail(&req->list, &dev->tx_reqs);
if (dev->port_usb->multi_pkt_xfer) {
dev->no_tx_req_used--;
req->length = 0;
in = dev->port_usb->in_ep;
if (!list_empty(&dev->tx_reqs)) {
new_req = container_of(dev->tx_reqs.next,
struct usb_request, list);
list_del(&new_req->list);
spin_unlock(&dev->req_lock);
if (new_req->length > 0) {
length = new_req->length;
/* NCM requires no zlp if transfer is
* dwNtbInMaxSize */
if (dev->port_usb->is_fixed &&
length == dev->port_usb->fixed_in_len &&
(length % in->maxpacket) == 0)
new_req->zero = 0;
else
new_req->zero = 1;
/* use zlp framing on tx for strict CDC-Ether
* conformance, though any robust network rx
* path ignores extra padding. and some hardware
* doesn't like to write zlps.
*/
if (new_req->zero && !dev->zlp &&
(length % in->maxpacket) == 0) {
new_req->zero = 0;
length++;
}
new_req->length = length;
retval = usb_ep_queue(in, new_req, GFP_ATOMIC);
switch (retval) {
default:
DBG(dev, "tx queue err %d\n", retval);
break;
case 0:
spin_lock(&dev->req_lock);
dev->no_tx_req_used++;
spin_unlock(&dev->req_lock);
net->trans_start = jiffies;
}
} else {
spin_lock(&dev->req_lock);
list_add(&new_req->list, &dev->tx_reqs);
spin_unlock(&dev->req_lock);
}
} else {
spin_unlock(&dev->req_lock);
}
} else {
spin_unlock(&dev->req_lock);
dev_kfree_skb_any(skb);
}
if (netif_carrier_ok(dev->net))
netif_wake_queue(dev->net);
}
static inline int is_promisc(u16 cdc_filter)
{
return cdc_filter & USB_CDC_PACKET_TYPE_PROMISCUOUS;
}
static void alloc_tx_buffer(struct eth_dev *dev)
{
struct list_head *act;
struct usb_request *req;
dev->tx_req_bufsize = (dev->dl_max_pkts_per_xfer *
(dev->net->mtu
+ sizeof(struct ethhdr)
/* size of rndis_packet_msg_type */
+ 44
+ 22));
list_for_each(act, &dev->tx_reqs) {
req = container_of(act, struct usb_request, list);
if (!req->buf)
req->buf = kmalloc(dev->tx_req_bufsize,
GFP_ATOMIC);
}
}
static netdev_tx_t eth_start_xmit(struct sk_buff *skb,
struct net_device *net)
{
struct eth_dev *dev = netdev_priv(net);
int length = skb->len;
int retval;
struct usb_request *req = NULL;
unsigned long flags;
struct usb_ep *in;
u16 cdc_filter;
spin_lock_irqsave(&dev->lock, flags);
if (dev->port_usb) {
in = dev->port_usb->in_ep;
cdc_filter = dev->port_usb->cdc_filter;
} else {
in = NULL;
cdc_filter = 0;
}
spin_unlock_irqrestore(&dev->lock, flags);
if (!in) {
dev_kfree_skb_any(skb);
return NETDEV_TX_OK;
}
/* Allocate memory for tx_reqs to support multi packet transfer */
if (dev->port_usb->multi_pkt_xfer && !dev->tx_req_bufsize)
alloc_tx_buffer(dev);
/* apply outgoing CDC or RNDIS filters */
if (!is_promisc(cdc_filter)) {
u8 *dest = skb->data;
if (is_multicast_ether_addr(dest)) {
u16 type;
/* ignores USB_CDC_PACKET_TYPE_MULTICAST and host
* SET_ETHERNET_MULTICAST_FILTERS requests
*/
if (is_broadcast_ether_addr(dest))
type = USB_CDC_PACKET_TYPE_BROADCAST;
else
type = USB_CDC_PACKET_TYPE_ALL_MULTICAST;
if (!(cdc_filter & type)) {
dev_kfree_skb_any(skb);
return NETDEV_TX_OK;
}
}
/* ignores USB_CDC_PACKET_TYPE_DIRECTED */
}
spin_lock_irqsave(&dev->req_lock, flags);
/*
* this freelist can be empty if an interrupt triggered disconnect()
* and reconfigured the gadget (shutting down this queue) after the
* network stack decided to xmit but before we got the spinlock.
*/
if (list_empty(&dev->tx_reqs)) {
spin_unlock_irqrestore(&dev->req_lock, flags);
return NETDEV_TX_BUSY;
}
req = container_of(dev->tx_reqs.next, struct usb_request, list);
list_del(&req->list);
/* temporarily stop TX queue when the freelist empties */
if (list_empty(&dev->tx_reqs))
netif_stop_queue(net);
spin_unlock_irqrestore(&dev->req_lock, flags);
/* no buffer copies needed, unless the network stack did it
* or the hardware can't use skb buffers.
* or there's not enough space for extra headers we need
*/
if (dev->wrap) {
unsigned long flags;
spin_lock_irqsave(&dev->lock, flags);
if (dev->port_usb)
skb = dev->wrap(dev->port_usb, skb);
spin_unlock_irqrestore(&dev->lock, flags);
if (!skb)
goto drop;
}
spin_lock_irqsave(&dev->req_lock, flags);
dev->tx_skb_hold_count++;
spin_unlock_irqrestore(&dev->req_lock, flags);
if (dev->port_usb->multi_pkt_xfer) {
memcpy(req->buf + req->length, skb->data, skb->len);
req->length = req->length + skb->len;
length = req->length;
dev_kfree_skb_any(skb);
spin_lock_irqsave(&dev->req_lock, flags);
if (dev->tx_skb_hold_count < dev->dl_max_pkts_per_xfer) {
if (dev->no_tx_req_used > TX_REQ_THRESHOLD) {
list_add(&req->list, &dev->tx_reqs);
spin_unlock_irqrestore(&dev->req_lock, flags);
goto success;
}
}
dev->no_tx_req_used++;
spin_unlock_irqrestore(&dev->req_lock, flags);
spin_lock_irqsave(&dev->lock, flags);
dev->tx_skb_hold_count = 0;
spin_unlock_irqrestore(&dev->lock, flags);
} else {
length = skb->len;
req->buf = skb->data;
req->context = skb;
}
req->complete = tx_complete;
/* NCM requires no zlp if transfer is dwNtbInMaxSize */
if (dev->port_usb->is_fixed &&
length == dev->port_usb->fixed_in_len &&
(length % in->maxpacket) == 0)
req->zero = 0;
else
req->zero = 1;
/* use zlp framing on tx for strict CDC-Ether conformance,
* though any robust network rx path ignores extra padding.
* and some hardware doesn't like to write zlps.
*/
if (req->zero && !dev->zlp && (length % in->maxpacket) == 0) {
req->zero = 0;
length++;
}
req->length = length;
/* throttle highspeed IRQ rate back slightly */
if (gadget_is_dualspeed(dev->gadget) &&
(dev->gadget->speed == USB_SPEED_HIGH)) {
dev->tx_qlen++;
if (dev->tx_qlen == (qmult/2)) {
req->no_interrupt = 0;
dev->tx_qlen = 0;
} else {
req->no_interrupt = 1;
}
} else {
req->no_interrupt = 0;
}
retval = usb_ep_queue(in, req, GFP_ATOMIC);
switch (retval) {
default:
DBG(dev, "tx queue err %d\n", retval);
break;
case 0:
net->trans_start = jiffies;
}
if (retval) {
if (!dev->port_usb->multi_pkt_xfer)
dev_kfree_skb_any(skb);
drop:
dev->net->stats.tx_dropped++;
spin_lock_irqsave(&dev->req_lock, flags);
if (list_empty(&dev->tx_reqs))
netif_start_queue(net);
list_add(&req->list, &dev->tx_reqs);
spin_unlock_irqrestore(&dev->req_lock, flags);
}
success:
return NETDEV_TX_OK;
}
/*-------------------------------------------------------------------------*/
static void eth_start(struct eth_dev *dev, gfp_t gfp_flags)
{
DBG(dev, "%s\n", __func__);
/* fill the rx queue */
rx_fill(dev, gfp_flags);
/* and open the tx floodgates */
dev->tx_qlen = 0;
netif_wake_queue(dev->net);
}
static int eth_open(struct net_device *net)
{
struct eth_dev *dev = netdev_priv(net);
struct gether *link;
DBG(dev, "%s\n", __func__);
if (netif_carrier_ok(dev->net))
eth_start(dev, GFP_KERNEL);
spin_lock_irq(&dev->lock);
link = dev->port_usb;
if (link && link->open)
link->open(link);
spin_unlock_irq(&dev->lock);
return 0;
}
static int eth_stop(struct net_device *net)
{
struct eth_dev *dev = netdev_priv(net);
unsigned long flags;
VDBG(dev, "%s\n", __func__);
netif_stop_queue(net);
DBG(dev, "stop stats: rx/tx %ld/%ld, errs %ld/%ld\n",
dev->net->stats.rx_packets, dev->net->stats.tx_packets,
dev->net->stats.rx_errors, dev->net->stats.tx_errors
);
/* ensure there are no more active requests */
spin_lock_irqsave(&dev->lock, flags);
if (dev->port_usb) {
struct gether *link = dev->port_usb;
const struct usb_endpoint_descriptor *in;
const struct usb_endpoint_descriptor *out;
if (link->close)
link->close(link);
/* NOTE: we have no abort-queue primitive we could use
* to cancel all pending I/O. Instead, we disable then
* reenable the endpoints ... this idiom may leave toggle
* wrong, but that's a self-correcting error.
*
* REVISIT: we *COULD* just let the transfers complete at
* their own pace; the network stack can handle old packets.
* For the moment we leave this here, since it works.
*/
in = link->in_ep->desc;
out = link->out_ep->desc;
usb_ep_disable(link->in_ep);
usb_ep_disable(link->out_ep);
if (netif_carrier_ok(net)) {
DBG(dev, "host still using in/out endpoints\n");
link->in_ep->desc = in;
link->out_ep->desc = out;
usb_ep_enable(link->in_ep);
usb_ep_enable(link->out_ep);
}
}
spin_unlock_irqrestore(&dev->lock, flags);
return 0;
}
/*-------------------------------------------------------------------------*/
static u8 host_ethaddr[ETH_ALEN];
/* initial value, changed by "ifconfig usb0 hw ether xx:xx:xx:xx:xx:xx" */
static char *dev_addr;
module_param(dev_addr, charp, S_IRUGO);
MODULE_PARM_DESC(dev_addr, "Device Ethernet Address");
/* this address is invisible to ifconfig */
static char *host_addr;
module_param(host_addr, charp, S_IRUGO);
MODULE_PARM_DESC(host_addr, "Host Ethernet Address");
static int get_ether_addr(const char *str, u8 *dev_addr)
{
if (str) {
unsigned i;
for (i = 0; i < 6; i++) {
unsigned char num;
if ((*str == '.') || (*str == ':'))
str++;
num = hex_to_bin(*str++) << 4;
num |= hex_to_bin(*str++);
dev_addr [i] = num;
}
if (is_valid_ether_addr(dev_addr))
return 0;
}
eth_random_addr(dev_addr);
return 1;
}
static int get_host_ether_addr(u8 *str, u8 *dev_addr)
{
memcpy(dev_addr, str, ETH_ALEN);
if (is_valid_ether_addr(dev_addr))
return 0;
random_ether_addr(dev_addr);
memcpy(str, dev_addr, ETH_ALEN);
return 1;
}
static const struct net_device_ops eth_netdev_ops = {
.ndo_open = eth_open,
.ndo_stop = eth_stop,
.ndo_start_xmit = eth_start_xmit,
.ndo_change_mtu = ueth_change_mtu,
.ndo_set_mac_address = eth_mac_addr,
.ndo_validate_addr = eth_validate_addr,
};
static struct device_type gadget_type = {
.name = "gadget",
};
/**
* gether_setup_name - initialize one ethernet-over-usb link
* @g: gadget to associated with these links
* @ethaddr: NULL, or a buffer in which the ethernet address of the
* host side of the link is recorded
* @netname: name for network device (for example, "usb")
* Context: may sleep
*
* This sets up the single network link that may be exported by a
* gadget driver using this framework. The link layer addresses are
* set up using module parameters.
*
* Returns negative errno, or zero on success
*/
struct eth_dev *gether_setup_name(struct usb_gadget *g, u8 ethaddr[ETH_ALEN],
const char *netname)
{
struct eth_dev *dev;
struct net_device *net;
int status;
net = alloc_etherdev(sizeof *dev);
if (!net)
return ERR_PTR(-ENOMEM);
dev = netdev_priv(net);
spin_lock_init(&dev->lock);
spin_lock_init(&dev->req_lock);
INIT_WORK(&dev->work, eth_work);
INIT_WORK(&dev->rx_work, process_rx_w);
INIT_LIST_HEAD(&dev->tx_reqs);
INIT_LIST_HEAD(&dev->rx_reqs);
skb_queue_head_init(&dev->rx_frames);
/* network device setup */
dev->net = net;
snprintf(net->name, sizeof(net->name), "%s%%d", netname);
if (get_ether_addr(dev_addr, net->dev_addr))
dev_warn(&g->dev,
"using random %s ethernet address\n", "self");
if (get_host_ether_addr(host_ethaddr, dev->host_mac))
dev_warn(&g->dev, "using random %s ethernet address\n", "host");
else
dev_warn(&g->dev, "using previous %s ethernet address\n", "host");
if (ethaddr)
memcpy(ethaddr, dev->host_mac, ETH_ALEN);
net->netdev_ops = ð_netdev_ops;
SET_ETHTOOL_OPS(net, &ops);
dev->gadget = g;
SET_NETDEV_DEV(net, &g->dev);
SET_NETDEV_DEVTYPE(net, &gadget_type);
status = register_netdev(net);
if (status < 0) {
dev_dbg(&g->dev, "register_netdev failed, %d\n", status);
free_netdev(net);
dev = ERR_PTR(status);
} else {
INFO(dev, "MAC %pM\n", net->dev_addr);
INFO(dev, "HOST MAC %pM\n", dev->host_mac);
/* two kinds of host-initiated state changes:
* - iff DATA transfer is active, carrier is "on"
* - tx queueing enabled if open *and* carrier is "on"
*/
netif_carrier_off(net);
}
return dev;
}
/**
* gether_cleanup - remove Ethernet-over-USB device
* Context: may sleep
*
* This is called to free all resources allocated by @gether_setup().
*/
void gether_cleanup(struct eth_dev *dev)
{
if (!dev)
return;
unregister_netdev(dev->net);
flush_work(&dev->work);
free_netdev(dev->net);
}
/**
* gether_connect - notify network layer that USB link is active
* @link: the USB link, set up with endpoints, descriptors matching
* current device speed, and any framing wrapper(s) set up.
* Context: irqs blocked
*
* This is called to activate endpoints and let the network layer know
* the connection is active ("carrier detect"). It may cause the I/O
* queues to open and start letting network packets flow, but will in
* any case activate the endpoints so that they respond properly to the
* USB host.
*
* Verify net_device pointer returned using IS_ERR(). If it doesn't
* indicate some error code (negative errno), ep->driver_data values
* have been overwritten.
*/
struct net_device *gether_connect(struct gether *link)
{
struct eth_dev *dev = link->ioport;
int result = 0;
if (!dev)
return ERR_PTR(-EINVAL);
link->in_ep->driver_data = dev;
result = usb_ep_enable(link->in_ep);
if (result != 0) {
DBG(dev, "enable %s --> %d\n",
link->in_ep->name, result);
goto fail0;
}
link->out_ep->driver_data = dev;
result = usb_ep_enable(link->out_ep);
if (result != 0) {
DBG(dev, "enable %s --> %d\n",
link->out_ep->name, result);
goto fail1;
}
if (result == 0)
result = alloc_requests(dev, link, qlen(dev->gadget));
if (result == 0) {
dev->zlp = link->is_zlp_ok;
DBG(dev, "qlen %d\n", qlen(dev->gadget));
dev->header_len = link->header_len;
dev->unwrap = link->unwrap;
dev->wrap = link->wrap;
dev->ul_max_pkts_per_xfer = link->ul_max_pkts_per_xfer;
dev->dl_max_pkts_per_xfer = link->dl_max_pkts_per_xfer;
spin_lock(&dev->lock);
dev->tx_skb_hold_count = 0;
dev->no_tx_req_used = 0;
dev->tx_req_bufsize = 0;
dev->port_usb = link;
if (netif_running(dev->net)) {
if (link->open)
link->open(link);
} else {
if (link->close)
link->close(link);
}
spin_unlock(&dev->lock);
netif_carrier_on(dev->net);
if (netif_running(dev->net))
eth_start(dev, GFP_ATOMIC);
/* on error, disable any endpoints */
} else {
(void) usb_ep_disable(link->out_ep);
fail1:
(void) usb_ep_disable(link->in_ep);
}
fail0:
/* caller is responsible for cleanup on error */
if (result < 0)
return ERR_PTR(result);
return dev->net;
}
/**
* gether_disconnect - notify network layer that USB link is inactive
* @link: the USB link, on which gether_connect() was called
* Context: irqs blocked
*
* This is called to deactivate endpoints and let the network layer know
* the connection went inactive ("no carrier").
*
* On return, the state is as if gether_connect() had never been called.
* The endpoints are inactive, and accordingly without active USB I/O.
* Pointers to endpoint descriptors and endpoint private data are nulled.
*/
void gether_disconnect(struct gether *link)
{
struct eth_dev *dev = link->ioport;
struct usb_request *req;
struct sk_buff *skb;
WARN_ON(!dev);
if (!dev)
return;
DBG(dev, "%s\n", __func__);
netif_stop_queue(dev->net);
netif_carrier_off(dev->net);
/* disable endpoints, forcing (synchronous) completion
* of all pending i/o. then free the request objects
* and forget about the endpoints.
*/
usb_ep_disable(link->in_ep);
spin_lock(&dev->req_lock);
while (!list_empty(&dev->tx_reqs)) {
req = container_of(dev->tx_reqs.next,
struct usb_request, list);
list_del(&req->list);
spin_unlock(&dev->req_lock);
if (link->multi_pkt_xfer)
kfree(req->buf);
usb_ep_free_request(link->in_ep, req);
spin_lock(&dev->req_lock);
}
spin_unlock(&dev->req_lock);
link->in_ep->driver_data = NULL;
link->in_ep->desc = NULL;
usb_ep_disable(link->out_ep);
spin_lock(&dev->req_lock);
while (!list_empty(&dev->rx_reqs)) {
req = container_of(dev->rx_reqs.next,
struct usb_request, list);
list_del(&req->list);
spin_unlock(&dev->req_lock);
usb_ep_free_request(link->out_ep, req);
spin_lock(&dev->req_lock);
}
spin_unlock(&dev->req_lock);
spin_lock(&dev->rx_frames.lock);
while ((skb = __skb_dequeue(&dev->rx_frames)))
dev_kfree_skb_any(skb);
spin_unlock(&dev->rx_frames.lock);
link->out_ep->driver_data = NULL;
link->out_ep->desc = NULL;
/* finish forgetting about this USB link episode */
dev->header_len = 0;
dev->unwrap = NULL;
dev->wrap = NULL;
spin_lock(&dev->lock);
dev->port_usb = NULL;
spin_unlock(&dev->lock);
}
static int __init gether_init(void)
{
uether_wq = create_singlethread_workqueue("uether");
if (!uether_wq) {
pr_err("%s: Unable to create workqueue: uether\n", __func__);
return -ENOMEM;
}
return 0;
}
module_init(gether_init);
static void __exit gether_exit(void)
{
destroy_workqueue(uether_wq);
}
module_exit(gether_exit);
MODULE_DESCRIPTION("ethernet over USB driver");
MODULE_LICENSE("GPL v2");